UV offset printing card printing process

1, printing process:

1 The design draft shall determine the output format according to the work order. Note that the angle of the cable is matched with the printed material to avoid collision.

2 Plates and blankets recommended to use UV special class PS version is not easy to deformation, dot reducibility is good, resistant to India, printing ink balance is good, the rubber becomes flexible, flatness is good, tensile strength, elongation Small, small amount of compression deformation.

3 The difference between the temperature and humidity of the printing ring mirror can not be too large, it needs to maintain a relatively stable balance, and it is very critical for improving the accuracy of overprinting; the temperature is generally controlled between 20-25°C, and the relative humidity is kept in between. 50-60%

4 Ink balance control is very critical for offset printing, especially for UV offset printing, and it must be a good step. UV offset ink ink has a very narrow range of balance. If it is not properly controlled, it can easily cause ink emulsification and dirty printing, seriously affecting product quality. Under normal circumstances, The conductivity of the fountain solution should be between 800-1200 uΩ/mm. It is recommended that the isopropyl alcohol (ethanol) in the fountain solution be 10-15%. The temperature should be controlled between 5°C and 8°C to increase the fountain solution. The surface tension, lower the temperature, so that it can reach the water and ink balance when less use, try to avoid the large amount of ink emulsion caused.

2, printing color sequence and curing conditions:

1 difficult to cure the first printing, easy to cure after the printing, four-color ink recommended printing sequence: black - blue - yellow - magenta, (because black and cryogenic color tone will absorb a lot of UV light, UV transmittance is very low In this way, everyone can be cured

(2) The first printing with strong dark or hiding power, the printing with light color transparency;

3 small area pattern, high color printing requirements of the first printing, large area of ​​the printing; then, on-site operation will need to combine several factors, to develop a reasonable, in line with the required printing order.

4 According to the color depth, hiding power, ink layer thickness, cold tone and dark color printing area is larger, it is recommended that curing energy 70-80 millijonles/cm-1 (uv-v), warm and light tone printing surface, it is recommended The curing energy is 45-60 millijonles/cm-1(uv-v). The specific needs are adjusted according to the site conditions. After the sample is recommended to be qualified before production, mass production is carried out.

3, substrate requirements:

The surface tension of printing materials requires PVC to reach 32 dynes or more, ABS needs to reach 34-36 dynes, and PET needs to reach 38-42 dynes. If it is lower, adhesion may be poor.

4, reasonable application of consumables:

1 When there is a large area of ​​printing or if the UV machine requires a long time and the temperature is high, the printed material will be curled and deformed due to printing, heat, etc., which will cause inconvenience to follow-up work. Therefore, it is necessary to control the curing time. The materials are properly stored to prevent deformation, and all processes must be closely linked, so as to increase production efficiency and complete all processes as soon as possible.

2UV Offset All car wash water, cleaning agent, and plate-making liquid, etc. are best used for special products. This reasonable use of UV ink sticks, blankets, etc. can both prolong its service life and ensure that the print product is consistent before and after printing. improve product quality.

3 Comprehensive field materials, equipment, environment and other factors, to develop a high efficiency, reasonable and economical printing process, and strict implementation of operations, so as to ensure the printing of qualified products and create better economic benefits.

5. Common problems in printing:

1 poor adhesion and sticky back;

A. The normal surface tension of printed materials is not enough and needs to be reprocessed or replaced;

B, curing is not complete, check the lamp is aging, whether to change or cure when the transmission speed is too fast, should be slowed down again;

C. The order of printing is wrong and should be readjusted;

2 Ink emulsification, adjustment of adjusting liquid, ink balance;

3 Inaccurate coloring may be due to:

A. The order of color printing is incorrect. Firstly, a small area pattern with high printing requirements is required, and a large area pattern is printed;

B. The material is deformed due to curing, etc. The curing time and the curing temperature should be reduced as much as possible, and the semi-finished products should be properly kept;

4 different shades of color need to be adjusted;

A. Check the ink and water balance;

B, check the ink roller pressure;

C. The difference of temperature and humidity on the site of the workshop is too great, which causes the ink viscosity to change too much. Attention must be paid to controlling the temperature and humidity at the scene.